<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>Document</title>
</head>

<body>
	<script>


let total = 30;
let msg = passthru`The total is ${total} (${total*1.05} with tax)`;

function passthru(literals) {	
  let result = '';
  let i = 0;

  while (i < literals.length) {
    result += literals[i++];
    if (i < arguments.length) {
      result += arguments[i];
    }
  }

  return result;
}
		
	</script>
</body>

</html>